Device and method for measuring plane parallelism of groove of large-diameter crosshead pin

Abstract

The invention discloses a device and a method for measuring the parallelism of a groove plane of a large-diameter crosshead pin. The device comprises a base, a stand column, a clamping block, a transverse column, a gauge clamp, a dial gauge and a measuring head, wherein the stand column is vertically fixed on the base, the clamping block is connected to the stand column and can slide up and down along the stand column to adjust the height position, the transverse column is horizontally connected to the clamping block and can move left and right on the clamping block to adjust the horizontal position, the gauge clamp is fixedly connected to the end portion of the transverse column, and the dial gauge is clamped on the gauge clamp. The measuring head is installed on the head of a measuring rod of the dial indicator. The height and the left-right position of the measuring head are adjusted through movement of the clamping block and the transverse column. The bases are sequentially placed at the two ends of the groove plane, indication values of the dial indicator are read out when the measuring head makes contact with a large outer circle generatrix, the difference value of the indication values at the two positions is calculated, and then the parallelism error value of the cross head pin groove plane and the large outer circle axis is obtained. The device is simple in structure and convenient to operate, achieves the effects of being accurate in measurement, improving efficiency and saving cost, and is suitable for measuring the parallelism of the groove planes of various cross head pins.

Description

Technical Field

[0001] The present invention relates to precision detection in the machining of large low-speed diesel engine parts, and specifically relates to a measuring device and method for the parallelism of the groove plane of a large-diameter crosshead pin, belonging to the technical field of mechanical precision measurement. Background Art

[0002] The crosshead pin is one of the important components of a large marine diesel engine. Refer to Figure 1 , the crosshead pin 1 includes a large outer circle 11 and a groove plane 12, belonging to a large cylindrical workpiece; taking the 12X92DF type crosshead pin of a large marine diesel engine as an example, the maximum diameter of its outer dimension is 920 mm, the total length is 1310 mm, and the weight is about 6.5 tons. When the marine diesel engine is running, the bottom of the piston assembly is connected to the crosshead pin 1 and is positioned by the groove plane 12 on the crosshead pin 1. If the parallelism error of this groove plane 12 is too large, it will directly affect the centering accuracy of the piston head after assembly, and ultimately affect the performance of the combustion chamber and the abnormal wear of components such as piston rings and cylinder liners. The most serious situation is the occurrence of cylinder scoring. Therefore, the parallelism accuracy of the groove plane is one of the key characteristics and quality control points of the crosshead pin. The cylindricity requirement of the large outer circle 11 of the crosshead pin 1 is 0.02 mm, and the parallelism requirement of the groove plane 12 is 0.02 mm. See Figure 1 , the composition element of this parallelism is the theoretical axis of the groove plane 12 of the crosshead pin 1 and the large outer circle 11 of the crosshead pin 1. Therefore, whether the parallelism of the groove plane 12 of the crosshead pin 1 meets the drawing requirements must be detected by a reliable method to determine the accuracy after the crosshead pin is finely machined.

[0003] At present, the commonly used parallelism detection methods in the field of mechanical technology are mainly divided into the measuring tool measurement method and the measuring equipment measurement method. The measuring tool measurement method includes a parallelism meter. This method is usually used for small parts, and the workpiece can be installed on the parallelism meter, but it is not suitable for measuring the crosshead pin of a large low-speed diesel engine. The measuring equipment measurement method mainly includes a coordinate measuring machine. First, a large coordinate measuring machine is required, and it has a lifting capacity. At the same time, the crosshead pin needs to be transported back and forth and kept at a constant temperature before measurement; although this method has high accuracy, it greatly increases the measurement cost and also fails to achieve the effect of rapid measurement.

[0004] In summary, the existing measurement methods do not adapt to the current situation of measuring the parallelism of the crosshead pin groove plane. Therefore, a small and low-cost device for achieving high-precision micron measurement of the crosshead pin parallelism is needed to meet the production requirements. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art and provide a measuring device and method for the parallelism of the groove plane of a large-diameter crosshead pin, so as to improve the detection accuracy of the parallelism of the groove plane after the finish machining of the crosshead pin of a large low-speed diesel engine, achieving the effects of convenient installation and use and ensuring the measurement accuracy.

[0006] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0007] A measuring device for the parallelism of the groove plane of a large-diameter crosshead pin, wherein the crosshead pin includes a large outer circle and a groove plane; characterized in that: the measuring device includes a base, a column, a clamping block, a cross column, a dial indicator clamp, a dial indicator and a measuring head;

[0008] The column is vertically fixed on the base by threads, the clamping block is fixedly connected to the column and can slide up and down along the column to adjust the height position, the cross column is horizontally fixedly connected to the clamping block and can move left and right on the clamping block to adjust the horizontal position, the dial indicator clamp is fixedly connected to the end of the cross column, the dial indicator is clamped on the dial indicator clamp, the measuring head is installed at the head of the measuring rod of the dial indicator, and the measuring head adjusts the height and left and right positions through the sliding of the clamping block on the column and the movement of the cross column on the clamping block;

[0009] The base is successively placed at both ends of the groove plane, the indicated values of the dial indicator when the measuring head contacts the generatrix of the large outer circle are respectively read out, and the difference between the two indicated values is calculated, that is, the parallelism error value between the groove plane of the crosshead pin and the axis of the large outer circle is obtained.

[0010] Further, the base is a cuboid, made of marble, the length of the lower plane is greater than 100 mm, the width is greater than 60 mm, and the flatness is within 0.005 mm.

[0011] Further, a threaded hole is provided at the central position of the upper plane of the base, and an external thread matching the threaded hole is provided at the bottom end of the column.

[0012] Further, the clamping block is provided with a vertical guiding through hole and a horizontal guiding through hole that are perpendicular to each other and do not communicate with each other. The clamping block is sleeved on the column through the vertical guiding through hole and can slide up and down along the column. After the height position is adjusted, it is fixed with screws. The cross column penetrates into the horizontal guiding through hole and can move left and right in the horizontal guiding through hole. After the horizontal position is adjusted, it is fixed with screws.

[0013] Further, the dial indicator clamp can move arbitrarily on the cross column and can rotate 360° around the axis of the cross column.

[0014] Further, the diameter of the measuring head is greater than 10 mm.

[0015] Another technical solution of the present invention is:

[0016] A measuring method for the parallelism of the groove plane of a large-diameter crosshead pin realized by the above measuring device, comprising the following specific steps:

[0017] Step 1, place the crosshead pin with the groove plane facing up;

[0018] Step 2, place the base on the groove plane of the crosshead pin to complete the combined assembly of the measuring device;

[0019] Step 3, loosen the screw on the clamping block, move the clamping block, adjust the height position of the cross column on the vertical column so that the measuring head on the dial indicator just touches the large outer circle, and then tighten the clamping block with the screw, and adjust the indication value of the dial indicator to the "0" position;

[0020] Step 4, at one end of the groove plane, place the base on the groove plane and slowly move it from one side to the other side. When the measuring head moves to the generatrix at the highest point of the large outer circle, record the indication value of the dial indicator. Then, at the other end of the groove plane, place the base on the groove plane and slowly move it from one side to the other side. When the measuring head moves to the generatrix at the highest point of the large outer circle, record the indication value of the dial indicator again. Subtract the indication values read at both ends to obtain the difference between the distances from the respective endpoints on the groove plane to the generatrix at the highest point of the large outer circle. This difference is the parallelism error value between the groove plane and the axis of the large outer circle.

[0021] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0022] 1. The present invention can quickly and accurately complete the measurement operation of the parallelism of the groove plane of the crosshead pin, fully meeting the production needs, and achieving the effects of accurate measurement results, improved operation efficiency, and cost savings in the process.

[0023] 2. The measuring device has strong versatility. By simply replacing components of different sizes, it can be applicable to the measurement of the parallelism of the groove planes of crosshead pins of various models and different sizes within a certain range.

[0024] 3. The present invention has the advantages of simple structure and convenient operation, and can be operated by a single person. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of a crosshead pin.

[0026] Figure 2It is a structural schematic diagram of the measuring device of the present invention.

[0027] Figure 3 It is a usage state diagram of the present invention.

[0028] In the figure:

[0029] 1 - crosshead pin, 11 - large outer circle, 12 - groove plane, 2 - base, 3 - column, 4 - clamping block, 5 - cross column, 6 - dial indicator clamp, 7 - dial indicator, 8 - measuring head. Specific embodiments

[0030] The present invention is used for measuring the parallelism of the groove plane of a large - diameter crosshead pin. Please refer to Figure 1 , in the figure, the crosshead pin 1 includes a large outer circle 11 and a groove plane 12; the groove plane 12 is a plane, with the axis of the large outer circle 11 as the reference, the parallelism error between the groove plane 12 and the axis of the large outer circle 11 is required to be within 0.02 mm, and this parallelism is the measurement object of the present invention.

[0031] The following will describe the present invention in detail with reference to the accompanying drawings and embodiments. The embodiments are not used to limit the scope of implementation of the present invention. Any equivalent changes and modifications made according to the content of the present invention application belong to the scope of the present invention.

[0032] Embodiment

[0033] Please refer to Figure 2 , the measuring device includes a base 2, a column 3, a clamping block 4, a cross column 5, a dial indicator clamp 6, a dial indicator 7 and a measuring head 8.

[0034] The base 2 has a cuboid structure, the material is marble, the length of the lower plane is greater than 100 mm, the width of the lower plane is greater than 60 mm, the parallelism of the lower plane is within 0.005 mm, and a threaded hole is provided at the center position of the upper plane of the base 2.

[0035] The bottom end of the column 3 is provided with an external thread, and the column 3 is vertically fixed on the base 2 by threaded connection.

[0036] The clamping block 4 is connected to the cylinder at the upper end of the column 3, and is provided with two mutually perpendicular and non - communicating guiding through - holes. The clamping block 4 is sleeved on the column 3 through the vertical guiding through - holes and is fixed on the column 3 by screws. The clamping block 4 can slide up and down along the column 3 to adjust the height position of the clamping block 4.

[0037] The cross column 5 is a round rod, one end of which passes through the horizontal guiding through hole of the clamping block 4 and is fixed by screws. The cross column 5 can move left and right in the horizontal guiding through hole of the clamping block 4 to adjust the horizontal position. The cross column 5 is arranged nearly perpendicular to the column 3. By moving the clamping block 4 up and down on the column 3, the cross column 5 also moves up and down accordingly.

[0038] The table clamp 6 is fixed at the other end of the cross column 5. The table clamp 6 can move to any position on the cross column 5 and can rotate 360° around the axis of the cross column 5.

[0039] The dial indicator 7 is arranged on the table clamp 6.

[0040] The measuring head 8 is installed at the head of the measuring rod of the dial indicator 7, and the diameter of the measuring head 8 is greater than 10 mm.

[0041] The measuring method for the parallelism of the groove plane of the large-diameter crosshead pin using the said measuring device is specifically as follows, as Figure 3 shown:

[0042] Step 1. After the crosshead pin 1 is processed, place the groove plane 12 facing upwards.

[0043] Step 2. Please refer to Figure 3 , place the base 2 on the groove plane 12 of the crosshead pin 1; screw the column 3 into the threaded hole on the upper plane of the base 2 for fixation. The column 3 and the cross column 5 are respectively inserted into the vertical guiding through hole and the horizontal guiding through hole of the clamping block 4. The cross column 5 is arranged nearly perpendicular to the column 3. By moving the clamping block 4 up and down on the column 3, the cross column 5 also moves up and down accordingly. At the same time, by moving the cross column 5 in the horizontal guiding through hole of the clamping block 4, the cross column 5 moves left and right, and then fix them with screws respectively. Then fix the table clamp 6 at the other end of the cross column 5, install the dial indicator 7 in the table clamp 6, and install the measuring head 8 with a diameter of 11 mm at the head of the measuring rod of the dial indicator 7.

[0044] Step 3. Loosen the screw on the clamping block 4, move the height position of the cross column 5 on the column 3 so that the measuring head 8 at the front end of the dial indicator 7 just touches the large outer circle 11 of the crosshead pin 1, and then tighten the clamping block 4 and adjust the indicated value of the dial indicator 7 to the "0" position.

[0045] Step 4. Slowly move the entire measuring device from one side to the other side of the groove plane 12 at one end of the groove plane 12. When the measuring head 8 moves to the generatrix at the highest point of the large outer circle 11, record the indicated value of the dial indicator 7, see Figure 3As shown, at the other end of the groove plane 12, slowly move the entire measuring device from one side of the groove plane 12 to the other side. When the measuring head 8 moves to the generatrix at the highest point of the large outer circle 11, record the indicated value of the micrometer 7 again; subtract the indicated values obtained at both ends to obtain the distance difference between the two endpoints on the groove plane 12 and the generatrix at the highest point of the large outer circle 11, and this distance difference is the parallelism error value between the groove plane 12 and the axis of the large outer circle 11;

[0046] Step 5. After the measurement is completed, remove the measuring device as a whole and place it properly.

[0047] For those of ordinary skill in the art to which the present invention pertains, without departing from the concept of the present invention, obvious equivalent transformations and alternative solutions that can be obtained without creative labor should all be regarded as falling within the scope of protection required by the present invention.

Claims

1. A measuring device for the parallelism of the groove plane of a large-diameter crosshead pin, the crosshead pin including a large outer circle and a groove plane; characterized in that: The described measuring device includes a base, a column, a clamping block, a cross column, a dial gauge clamp, a micrometer, and a measuring head; The column is vertically fixed on the base by threads. The clamping block is fixedly connected to the column and can slide up and down along the column to adjust the height position. The cross column is horizontally fixedly connected to the clamping block and can move left and right on the clamping block to adjust the horizontal position. The dial gauge clamp is fixedly connected to the end of the cross column. The micrometer is clamped on the dial gauge clamp. The measuring head is installed at the head of the measuring rod of the micrometer. The measuring head adjusts the height and left and right positions through the sliding of the clamping block on the column and the movement of the cross column on the clamping block; The base is successively placed at both ends of the groove plane. The indicated values of the micrometer when the measuring head contacts the generatrix of the large outer circle are read respectively, and the difference between the two indicated values is calculated, that is, the parallelism error value between the groove plane of the crosshead pin and the axis of the large outer circle is obtained.

2. The measuring device for the parallelism of the groove plane of a large-diameter crosshead pin according to claim 1, wherein: The described base is a cuboid, made of marble, the length of the lower plane is greater than 100 mm, the width is greater than 60 mm, and the flatness is within 0.005 mm.

3. The measuring device for the parallelism of the groove plane of a large-diameter crosshead pin according to claim 1, characterized in that: A threaded hole is provided at the central position of the upper plane of the base, and an external thread matching the threaded hole is provided at the bottom end of the column.

4. The measuring device for the parallelism of the groove plane of a large-diameter crosshead pin according to claim 1, wherein: The clamping block is provided with a vertical guiding through hole and a horizontal guiding through hole that are perpendicular to each other and do not communicate with each other. The clamping block is sleeved on the column through the vertical guiding through hole and can slide up and down along the column. After the height position is adjusted, it is fixed with screws. The cross column penetrates into the horizontal guiding through hole and can move left and right in the horizontal guiding through hole. After the horizontal position is adjusted, it is fixed with screws.

5. The measuring device for the parallelism of the groove plane of a large-diameter crosshead pin according to claim 1, characterized in that: The dial gauge clamp can move arbitrarily on the cross column and can rotate 360° around the axis of the cross column.

6. The measuring device for the parallelism of the groove plane of a large-diameter crosshead pin according to claim 1, characterized in that: The diameter of the described measuring head is greater than 10 mm.

7. A method for measuring the parallelism of the groove plane of a large-diameter crosshead pin, implemented by the measuring device according to claim 1, characterized in that: The described measuring method includes the following specific steps: Step 1, place the crosshead pin with the groove plane facing up; Step 2, place the base on the groove plane of the crosshead pin to complete the combined assembly of the measuring device; Step 3, loosen the screw on the clamping block, move the clamping block, adjust the height position of the cross column on the column so that the measuring head on the micrometer just touches the large outer circle, and then tighten the clamping block with screws and adjust the indicated value of the micrometer to the "0" position; Step 4, at one end of the groove plane, place the base on the groove plane and slowly move it from one side to the other side. When the measuring head moves to the generatrix at the highest point of the large outer circle, record the indicated value of the micrometer. Then, at the other end of the groove plane, place the base on the groove plane and slowly move it from one side to the other side. When the measuring head moves to the generatrix at the highest point of the large outer circle, record the indicated value of the micrometer again. Subtract the indicated values read at both ends, that is, obtain the difference between the distances from the two endpoints on the groove plane to the generatrix at the highest point of the large outer circle respectively. This difference is the parallelism error value between the groove plane and the axis of the large outer circle.

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